Machine for making spring dowel pins



Jan. 8, 1952 PETERS si' AL MACHINE FOR MAKING SPRING DOWEL PINS Filed July 30, 1948 6 Sheets-Sheet 1 r e w mi L V E n@ Q i@ y M M\J mhd Q nmi r mw www @ook 9m. MM Mm o wk K n a Si [www EN n. /mw n wf Q n N* mm. t muv Mv mb.

by n a@ m75 Jan. 8, 1952 H. PETERS ETA.

MACHINE OR MAKING SPRING DOWEL PINS 6 Sheets-Sheet 2 Filed July 30, 1948 n. i h l ow ow rm-m ww fl wm I mm. I..

Jan. 8, 1952 H. PETERS ErAL 2,582,062

MACHINE FOR MAKING SPRING DOWEL PINS Filed July so, "1948 s sheets-sheet s -Fz q 9 76e /0/ lla 75a I 75d VEN/D 2"5 ommen pff-fes Jan. 8, 1952 H. PETERS ETAL PRING DOWEL PINS File d July 30' 19 P7 q- 1o. 76 /l ,l

// YlI n/ F? Q- 11. /f l Jan. 8, 1952 H. PETERS ETAL MACHINE FOR MAKING SPRING DOWEI.. PINS 6 Sheets-She'et 5 Filed July 30, 1948 Jan. 8, 1952 H. PETERS ETAL MACHINE FOR MAKING SPRING DOWEL PINS 6 Sheets-Sheet 6 Filed July 30, 1948 w wk 8mm mwihm Partented Jan. 8, 1952 MACHINE FOR MAKING SPRING v DOWEL PINS Howard Peters, Des Plaines, and Edward J.

Haedike, Chicago, Ill., assignors, by mesne assignments, to Elastic Stop Nut Corporation of America, Union, N. J., a corporation of New Jersey Application July 30, 1948, Serial No. 41,683

y (Cl. 153-2) 8 Claims.

This invencarelates to the production of tubular metal pins having a slot or gap along their length and generally referred to as tubular pins. More particularly, the invention deals with an apparatus for accurately forming tubular pins of any desired length from spring steel stock.

While it has been recognized that spring steel tubular pins are highly desirable fasteners and connectors in the mechanical arts and are especially effective as keys, bearing pins, dowel pins, clevis pins, and the like because of their light weight, strength, lubricant-conveying capacity and ability to adapt themselves to various tolerance dimensions, it has not heretofore been possible to accurately produce suitable tubular pins on an economic commercial scale. Prior attempts to produce tubular pins have included the cutting of tubes into the desired lengths and the longitudinal milling of slots along the length of the cut tubes, as well as punch press deformation of stamped out blanks. These procedures have required iinishinng operations and successive handling which render the prior practices too slow and costly to compete with the production of solid pins and keys.

According to the present invention, tubular pins are accurately formed from spring steel strip stock. The steel strip preferably has the metal grain thereof extending parallel with the length of the strip and preferably has beveled or chamfered side edges. Slugs are cut from the strip. The width of the strip determines the length of the tubular pin, and the length of the cut-off slug determines the circumference of the tubular pin. Thus, the grain of the metal extends around the circumference of the pin to increase the strength and wearing capacity of the pin, since the only pin surface defined by the grain band ends will be the edges of the pin defining the slot or gap. 1 The ends of the pin are defined by the chamfered or beveled sides of the strip and thus have tapered contours to facilitate insertion of the pin in a hole. The machine for producing the pin includes a cutter and feeder for cutting the slugs from the strip and for feeding these slugs in end-to-endV relation to a series of forming rollers. 'I'hese forming rollers are composed of mating pairs of rollers with peripheral contours that are so shaped as to form nips which will successively curl the slugs to the desired tubular pin dimension.

An important feature of this invention resides in the initial bending of the side margins of the slugs to the shape they will have in the final tubular pin, then successively deforming the l vention resides in its ability to produce tubular pins of desired sizes by substituting forming rolls or Wheels as desired and by setting the cutting mechanism as desired.

Another important feature of the machine resides in the arrangement of the forming rolls or wheels to not only accurately curl the metal slugs to the desired contour but to also accurately maintain a uniform gap or slot in the tubular pin.

Another important feature of the machine of the invention is the provision of guides for feeding the slugs and partially formed tubular pin blanks at one level into the nips of the forming rolls or wheels and to receive the partially formed tubular pins from the nips at a different level while holding the slugs and blanks against axial and radial misalignment and longitudinal bending around the periphery of a forming roll.

A further important feature of the machine resides in the provision of tubular pin centering ribs on the forming rolls to hold the pin in .proper position for the pin-forming operations.

An object of the invention is to provide a spring metal tubular pin having the grain of the metal extending around the circumference of the pin and having beveled end faces for facilitating insertion of the pin.

A still further object of the invention is to provide a machine for accurately forming tubular pins from flat metal slugs at high speeds without wastage of metal.

A still further specic object of the invention is to provide a continuous roll mill for successively curling at metal slugs around mandrels while holding the slugs against rotation so that close tolerance limits are maintained in both the circumferential dimensions and the slot dimensions of the tubular pins.

Another object of the invention is to provide a roll mill for shaping metal slugs between forming rolls wherein the slugs are accurately fed to and received from the nips of the forming rolls by guides which are designed to hold the successive shapes in predetermined end-to-end relationship.

Another object of the invention is to provide a continuous roll mill for successively deforming 5 metal slugs wherein al series of pairs of complementary' forming rolls are suitably driven by shafts .iournaled in an upstanding plate and wherein the shafts are driven at properly correlated speeds from a single source through the media of sprockets and chains, or gears.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings, which, by way of a preferred example, illustrate one form of machine according to this invention, together with the tubular pins produced thereby.

On the drawings:

Figure 1 is a group of isometric views illustrating strip stock for forming the tubular pins of the invention, a at slug cut from the strip stock, and a nished tubular 'pin produced from the slug.

Figure 2 is a broken, side elevational view of the tubular pin forming machine including the cutting and feeding mechanism and the roll mill.

Figure 3 is a fragmentary transverse crossv sectional view taken substantially along the line III-III of Figure 2 and illustrating the cutting of the metal strip stock into slugs and the feeding of the slugs to the roll mill portion of the machine.

Figure 4 is a broken top plan view of the roll mill portion of the machine.

Figure 5 is a longitudinal cross-sectional view, with parts in front end elevation, taken substantially along the line V-V of Figure 4.

Figures 6 to 15, inclusive, are enlarged, fragmentary cross-sectional views through the nips of the successive pairs of forming rolls in the roll mill section of the machine and illustrating ten passes for the machine.

Figure 16 is an enlarged fragmentary, longitudinal cross-sectional view taken through the nip area of the first set of forming rolls along the line XVI--XVI of Figure 6 and also illustrating the inlet and outlet guide fingers for the slug and partially formed tubular pin.

Figure 17 is a top plan view of the lower forming roll and the guide members shown in Figure 16.

Figures 18 and 19 are transverse cross-sectional views taken along the lines XVIII--XVIII and XIX-XIX of Figure 16.

Figure 20 is a cross-sectional view similar to Figure 16 but taken through the forming rolls of Figure 9 along the line XX--IDI thereof.

Figure 21 is a view similar to Figures 16 and 20 taken along the line XXI-XXI of Figure 12.

As shown on the drawings:

In Figure 1, the reference numeral I0 designates a strip of spring steel from which the tubular pins of this invention are formed. The spring steel is preferably a steel containing .092 to 0.10% carbon, such as S. A. E. 1095. Such steel, after being formed into the tubular pins, can be heat-treated in salt baths to develop suitable Rockwell hardnesses of about 52 C. The strip I n is chamfered or beveled along the side edges thereof to provide tapered walls Illa converging toward one face of the strip. The grain of the metal extends longitudinally along the length of the strip as illustrated at I0b so that the beveled sides I 0a are defined by the sides of the grain bands, and the ends of the grain bands are only exposed at the leading edge of the strip.

Slugs II are cut from the leading edge of the strip I0 and, of course, have beveled ends Illa and the grain band configuration l0b of the strip. The length of the leading end p0rti0n which is 4 e cut to form the slug II determines the circumferential dimension of the tubular pin since the slug is curled in the direction of the grain Ib to form the tubular pin I2. As illustrated, vthe grain bands I0b extend around the circumference of the tubular pin, and the beveled sides Ilia of the slug form tapered ends I0a on the tubular pin with the taper converging toward the inside diameter of the tubular pin to form reduced diameter tapered end portions on the tubular pin facilitating insertion of the tubular pin in a hole or keyway. The pin I2 has a slot or gap I2a of controlled uniform width along its entire length.

'I'he tubular pins of this invention are thus formed from flat 'spring steel strip stock by cutting off successive leading end portions of the strip to form slugs having a length determined by the width of the strip to control the length oi' the tubular pin and having a width determined by the length of the cut-off section to control the circumferential dimension of the tubular pin. Very short tubular pins are formed as accurately as longer pins.

The machine I3 of this invention for making the tubular pins I2 from the strip stock I0 includes, as shown in Figure 2, a cutter and feeder mechanism I4 and a roll mill assembly I5 mounted on a frame I6 having a horizontal top I1 supporting the sub-frames of the assemblies I4 and I5. The frame I6 includes legs or uprights I3 carrying the top I1 and preferably also supporting a shelf I 9 in spaced relation under the top I1 to rigidify the legs and to carry a. prime mover such as an electric motor 20.

The cutting and feeding assembly I4 includes an upstanding frame 2| mounted on the top I1 of the main frame I6 and equipped with bearing supports 22 at its upper end. These bearing supports 22 are in spaced relation and receive a shaft 23 therethrough and through the space therebetween. A flywheel 24 is secured on one end of the shaft 23, and sprockets 25 and 26 are secured on the other end of the shaft 23. The sprocket 25 is driven through a chain 21 by an electric motor (not shown). The sprocket 26 drives a chain 28 which actuates a worm shaft 29 to drive a worm wheel 30.

A pair of feed rollers 3| are rotatably mounted in bearings 32 provided on the frame 2i and receive the strip I0 therebetween. 'I'he rollers are preferably geared together by gears 33 and an axle shaft 34 on the lower roller 3| carries the worm gear 30 so that power for rotating the feed rollers is imparted from the driving motor through the chain 28 and worm shaft 29.

An eccentric 35 is mounted on the shaft 23 between the bearings 22, and a shear block 36 slidably mounted in the frame 2I is pinned to this eccentric to be raised and lowered thereby as the shaft 23 is rotated.

As best shown in Figure 3, the metal strip III from the feed rollers 3I is fed through a slot 31 in a covered block 38 to a feed table 39 which is rockably mounted on the frame 2l to pivot about a pin 40. A spring 4I acts upwardly on the feed table 39 to raise the discharge end of the table. A groove 42 extends through the table to receive the stock III from the groove 31. The leading end of the table lies adjacent a cutter knife 43 carried by the shear block 36 and has an insert 44 of tool steel or the like hard material to form a cutting edge for cooperation with the cutter 43. The strip I0 is fed over the top of the insert 44, and the cover forming the top wall of the groove 42 terminates in spaced relation from the cutter 43 to expose a portion of the'top of the insert 44.

An upstanding rib 46 is provided on the frame 2I in front of the rocking table 39 to provide a support for slugs II cut from the stock I0. This rib cooperates with a plate 46 on a block 41 to form a track or guide for the slugs II and a slot 48 is provided between the plate and rib to receive upstanding ejector fingers 49 on a chain 68 which has an upper run guided between spaced opposed lugs 6l.

As shown in Figure 2, the chain 66 is trained around sprockets 62, and one of the sprockets 62 is driven from the worm shaft 29 so that the ejector fingers 49 will pass through the slot 46 and successively strike against the cut-off slugs II and eject the same out of the cutter.

As shown in Figure 3, the spring 4I tilts the table 39 upwardly so that the leading end of the strip III will abut the cutter 43 to st op further forward movement of the strip. The feed rollers 3| can be continually driven, but since the length of the strip between the feed rollers and the cutter 43 is confined in the grooves 31 and 42, the strip cannot buckle when its forward movement is stopped by the cutter 43 and the rolls will merely slip on the strip until the cutter is raised above the leading end thereof, whereupon the feed rollers will advance the leading end of the strip to the abutment plate 53. 'I'his plate 53Y is adjustably mounted on the block 41 to control the distance between the cutting edge of the insert 44 and the abutment edge, thereby controlling the width of the slug II as desired.

When the eccentric 35 moves the shear bar 36 downwardly, the cutter 43 acts on the top of the strip I and cooperates with the insert 44 to shear off the slug II. The slug I I immediately drops on top of the rib 45 and plate 46 into the path of the ejector fingers 49 which discharge the slug. Forward movement of the strip I0 is arrested until the cutter 43 is raised by the eccentric 35 above the leading edge of the strip. The spring 4I is effective to raise the leading edge of the strip above the cutting edge of the cutter as soon as the slug I I is severed from this leading edge, so that the strip will not be advanced by the feed rollers 3| until the cut-off slug is ejected and the cutter has been raised on the next stroke thereof.

The assembly I4 thus lreceives the strip I0, cuts the slugs II from the leading edge of the strip. and ejects these slugs in end-toend relation at right angles to the strip. 'Ihe slugs are received in a guide track 54 (Figure 1) bridging the space between the slotted track afforded by the rib 45 and plate 46 and the roll mill assembly I5. This roll mill assembly includes upstanding front and rear walls 55 and 56 in spaced parallel relation mounted on the table I1.

As shown in Figures 2, 4 and 5, a plurality of lower shafts 51 and a plurality of upper shafts 58 bridge the space between the walls 55 and 56 and extend through the front wall 55. The shafts 51 and 58 are arranged in pairs with each pair being geared together by gears 59 and 60. Bearings for both ends of the top shafts 58 are mounted in slide blocks 6I in the front and rear walls so that the levels of these shafts are controlled with adjusting screws 62 for adjusting the top forming wheels relative to bottom wheels carried by the bottom shafts 51 which are mounted in fixed bearings in the walls 55 and 56.

A longitudinal drive shaft 63, as best shown in Figures 4 and 5, is rotatably mounted in bearings between the'walls 66 and llat alevel below the bottom shafts 61. This driveshaft 62 is driven through belts 64 from the motor 26. as shown in Figure 1. A Vworm 66 is provided on the shaft 63 to drive a gear 66 on the first bottom shaft 61 the roll mill assembly.. This first shaft 61 h a sprocket .61. thereonimmediately behind the` front wall 66, and the sprocket 61 drives a chain 68 which is meshed with a sprocket 69 on the second lower shaft 61 and a sprocket 10 on the third lower shaft 61'. Thus, the first three shafts 61 are connected by the samechain 68.v 'Ihe third shaft 61 containing the sprocket 10 also carries a sprocket 1I which drives a chain 12, and this chain in turn drives the next two bottom shafts (not shown). Additional chains and sprockets on the successive lower shafts 61 likewise transfer the driving power to all of the shafts. The size of the sprockets will determine the speed of rotation of the shafts, and as will be hereinafter more fully explained, the relative speeds of the shafts are so correlated as to pre- .vent the possibility of jamming of the slugs as they are successively fed through the various passes provided by the nips of the forming wheels. Idler sprockets 12, shown in Figure 5, can be mounted on shafts journaled in the front wall 55 to hold the chains in desired taut condition.

In the illustrated machine, each chain connects three adjacent bottom shafts 61 and the speeds of successive shafts are increased by decreasing the number of teeth on the sprocket carried by the shaft. Thus, the first chain 68 is driven by the sprocket 61 which has more teeth than the sprocket 69 on the second shaft, and this sprocket 69 .in turn has more teeth than the sprocket 10 on the third shaft. As a result, the shafts will be driven at ascending rates of speed. The sprocket 1I preferably has the same number of teeth as the sprocket 61 so that the chain 12 actuated by the third shaft 51 will be driven at a somewhat higher speed than the chain 66. and the two sprockets driven by this chain will have less teeth than the sprocket 1I so that their shafts will be driven at faster rates of speed. In the illustrated machine, therefore, the chains each drive groups of three shafts and the succeeding shafts in each group are driven at increased rates of speed. Likewise, the successive groups of shafts are driven at increased rates of speed. The net result is to increase the rate of speed successively from the first to the last bottom shaft.

The rolls or wheels are detachably mounted on the front ends of the shafts 61 and 58 in front of the front wall 55, and, as illustrated, nuts 14 can conveniently be threaded onto the front ends of the shafts for holding the forming rolls thereon. The lower shafts carry rolls or wheels designated generally by the reference numeral 15, while the upper shafts carry mating rolls or wheels designated by the reference numeral 16. All of these mating pairs of rolls or wheels except the first pair (designated 15' and 16') are male and female rolls or wheels with mating contoured peripheries acting on the slugs and blanks as they pass through the nips defined by the pairs of rolls. The first pair of wheels 15 and 16' are feeders acting on the slugs in the track 54 to advance these slugs to the first forming pass of the wall provided by the first pair of contoured male and female wheels 15a and 16a. The track 54 extends through the nip of the feeder wheels 15' and 16' and is slotted in the nip area of the wheels to allow the wheels to engage the slugs II in the track.

In order to properly guide and hold the slugs and blanks as they pass through and between the passes or nips of the pairs of contoured forming wheels, the front wall 58 carries in the line of the track I, a series of guide plates or fingers generally designated by the reference numeral 11. These fingers each have different contours as will be hereinafter explained and are mounted in end-to-end relation on brackets carried by the front wall 85.

As best illustrated in Figures l, 6, 16, 18 and 19, a slug II advanced by the feeder wheels 15 and 18' is received from the guide'track 54 into the first guide nger 11a. This guide finger 11a is composed of a flat bottom plate 18 and a grooved top plate 19 having a groove 88 in its bottom face deeper than the thickness of the slugs I I received therein and having a width such as to slidably guide the slugs in end-to-end relation. Thus, as illustrated in Figure 18, the width ofthe groove 88 is only slightly greater than the width of the slug II but has a depth about one and one-half times the thickness dimension of the slugs, so that the slugs cannot cock or overlap as they are advanced along the groove. The first guide finger 11a extends from the feeder track 54 into the nip of the first pair of forming wheels composed of the bottom male wheel 15a and the top female wheel 16a. As best shown in Figure 6, the male wheel 15a has a contoured periphery including a flat outer peripheral mandrel wall 8l with a central groove 82 therein. The wall 8| has rounded ends 8Ia dimensioned to form the nal shape for the side margins of the slugs. 'I'hese ends extend to flat shoulders 83. The shoulders 83 extend axially outward to flat radial walls 84. The walls 84 extend radially inward to axially outward extending fiat shoulders 85, and these shoulders 85 in turn extend axially outward to radial walls 86. The walls 86 in turn extend inward to a third pair of axial shoulders 81. Thus, the first male forming roll 15a has a stepped peripheral contour terminating in a flat circumferential mandrel wall 8l which has rounded sides 8 Ia and a central peripheral recess formed by the groove 82. The wall 8I and its ends Bia, as will hereinafter be explained, constitute the mandrel for forming the sides of the slugs into the shapes that they will have in the final roll pin.

As also shown in Figure 6, the first female forming wheel 16a has a contoured periphery with stepped shoulders and side walls forming a complementary recess for the stepped contour of the male roll 15a. However, the complementary recess deviates in some respects from the exact shape of the periphery of the male roll in order to accommodate the slug and to prevent binding. Thus, as shown in Figure 6, the recess in the female roll 16a has a rounded corner 88 between the at shoulder 89 which complements the shoulder 85 of the male roll, and this rounded corner merges inw a slightly converging side wall 98 facing the radial wall 84 of the male member. This rounded corner 88 and sloping side wall 98 provide the first zone for initially receiving the slug II as it enters the nip between the first pair of forming rolls, and the contours are designed to smoothly guide the sides of the slug toward the bottom of the recess. The converging or tilted walls 98 should have an angle greater than 3 and less than 45 from the radial or vertical plane of the wheels. The walls 98 converge to semi-circular grooves 9| which are opposite the shoulders 83 of the male member. These grooves provide clearance zones. since during the initial deformation of the fiat slugs II, they become appreciably wider and a clearance must be provided to permit their edges to swing through an arc as these edges are turned to form the first blank or slug piece IIa which has a channel shape with a flat web and arcuately curved side flanges.

The bottom of the recess in the female roll 18 is flat as at 92 to complement the wall 8l of the male member. The walls 8I and 92 are spaced apart in the center of the nip for a distance which is equivalent to the thickness of the slug. 'I'he wall 92, like the wall 8l, has rounded ends 92a complementing the ends 8Ia.

As illustrated in Figures 16 and 17, and as pointed out hereinabove, since the slugs II are relatively short, they must be guided and held as they are acted upon by the forming wheels so that they will not be curved along their length in conformity with the periphery of the wheels. For this purpose, the guide fingers are so arranged as to extend deep into the nips of the various passes. Thus, the first guide finger 11a has the top plate 19 thereof milled at 19a into conformity with the contour of the top wheel 18a to relieve the plate so that it will not strike against the Wheels. The bottom plate 18 is similarly milled at 18a. AThe milled cuts 18a and 19a extend inwardly to an unmilled central portion which can fit intoy the recess of the female roll under the shoulder 89 thereof. This central portion then extends forwardly into the nip and must be further reduced in width by milled portions 19h which permits clearance between the wall portions 98. The milled portions 19h have deeper milled inner ends 19c to accommodate the taper of the wall 98 as the central portion of the finger projects further into the nip. 'Ihe inner end of the finger is milled at 19d to follow the contour of the recess wall 92 as it enters the nip. It should be understood, of course, that the bottom face of the bottom plate 18 is similarly milled so that it eventually terminates in a reduced milled finger portion 18d beneath the portions 19d.

As explained hereinabove, the recess or slot 88 in the finger 11a is deeper than the slug I I by a dimension which is less than the thickness of the slug so that it is impossible for the slugs to overlap. However, the deep recess does permit raising of the slugs as they pass into the nip as illustrated in Figure 16.

As explained above, it is important that the slugs be held against deformation along their length in order that straight tubular pins may be insured. The guide fingers on the inlet sides of the nips thus direct the slugs into the nips at a low level where they can be received into the wider portion of the recess in the female roll, and as the male roll forces the leading end of each slug into its deformed shape and thus moves it deeper into the recess of the female roll, the slug rises to a higher level while still being retained in the groove 88. This is permitted by the clearance above the slug afforded by the deep groove. At the same time, however, the fingers hold the slug in a fiat condition and prevent it from being cocked or twisted out of its axial position.

As indicated in Figure 6, the first pass between the wheels 15a and 16a deforms the fiat slug II to form the first blank I la. This blank Ila has a fiat main web portion with downturned rounded ends. Since the slug, as explained above, enters the nip between the wheels at one level and is forced up into the female roll to a higher level, the deformed slug or blank IIa is ejected out of the nip at this higher level as illustrated in Figure 16. In order to hold the rst blank I Ia against further deformation, a second set of guide fingers 11b is provided. 'I'his set of guide fingers 11b includes a bottom plate 93 and a grooved top plate 94 shown in Figures 16, 17 and 19. The top plate 94 has a groove 95 in its bottom face covered by the bottom plate 93 and sized to accommodate the passage of the blank IIa therethrough. The plates 93 and 94 are milled similar to the plates 18 and 'I9 so as to clear the stepped shoulders of the forming wheels and to project deeply into the nips. Since the finger 11b is at a higher level than the finger 11a, the contour of the milling will be somewhat different, but it does include the milled outer forward corners 94a of the top plate and 93a of the bottom plate which terminate in the relatively sharp edge to fit close to the shoulders 89 of the Wheel 16a and provide a portion of reduced width which extends between the walls 90 and is milled at 94h to extend to a still further reduced portion which is milled at 94e so that it can penetrate deep into the innermost portion of the recess in the female wheel. In addition, however, the guide finger 11b has a raised rib 95 on the bottom plate 93 extending into the central portion of the groove 95 as best shown in Figure 19, so that the rounded edges of the blank IIa can fit around the rib 96. The rib 96 projects beyond the end of the finger 11b into the groove 82 in the wheel 15a, and this projecting tongue portion 96a receives the slug in the nip before the slug leaves the groove 80 to prevent the slug from following the contour of the roll a.

As illustrated in Figure 16, the leading end of the slug being deformed in the nip is raised by the male wheel 15a into the recess of the vfemale wheel 16a, thereby moving the slug from the bottom tothe top of the groove 80 and the tongue 96a thereupon immediately receives the leading end of the slug to guide it into the groove 95 of the finger 11b. Since the tongue and rib are of less width than the space between the downturned portions of the blank a, the blank will be centered on the rib as it advances through the groove 95.

The blanks ||a are advanced in succession by the rotating wheels 15a. and 16a through the groove 95 to the next nger '||c (Figures 4 and 5) which guides the blanks into the nip of the second pair of wheels 15b and 16h shown in Figure 7. These wheels are relieved and contoured to Work only on increments of the blank Ila which are adjacent the curved side margins formed by the first pair of rolls to form a blank b as shown in Figure '7. Thus. the blank ||a is initially fed by the finger 'l'lc between the converging walls 91 of the female wheel 1Gb which will not deform the downturned ends of the blank and is forced to the bottom of the recess against the fiat bottom Wall 98 by the mandrel surface 99 on the male wheel 15b. The bottom of the recess has curved ends 98a inwardly from the downturned ends of the blank Ila to extend the curvature inwardly into the flat web or wall of the blank. The mandrel portion 99 of the male wheel 15b has complementary curved portions 99a. As a result, the blank IIb is formed from the blank ||a and has a channel shape with a narrower flat Web and with deeper curved side flanges than the blank Ila to continue the circular deformation of the blank. 'Ihe male wheel 15b has the same recess 82 as the wheel 15a, and the next finger 11d has a tongue end of a guide rib projecting in this recess to receive the blank IIb from the nips of the wheels.

The blank progresses through and is deformed by the second set of wheels in substantially the same manner as illustrated in Figures 16 and 17 to extend the degree of deformation of the sides of the blank while maintaining the central portion of the blank in a substantially flat condition.

The third, fourth, fifth and sixth passes afforded by the rolls shown in Figures 8 to 11 are not included in Figures 4 and 5, but it will be understood that these passes as illustrated in Figures 8 to 1l are for the purpose of bowing the web portion of the blank into a more circular form and that the guide fingers feed the blanks to these rolls at one level and remove the further deformed blanks from the nips of these rolls at a higher level in the same manner described in connection with the previous passes, except, of course, that the tongues projecting into the groove 02 of the first two passes are eliminated.

The third set of rolls, designated as the male roll 15e and the female roll 16e, and shown in Figure 8, are contoured to form a blank ||c from the blank I Ib, wherein the fiat wall of the blank ||b is partially curved. The blank ||b is fed by the next nger between the converging side walls |00 of the female roll 16e and is forced by the male roll into the bottom of the recess against the arcuate bottom wall |0| thereof by the arcuate peripheral rib |02 on the male roll. As shown in Figure 8, the downturned ends of the blank are caused to curl inwardly by deformation of the fiat web of the blank ||b into the bowed web of the blank Ic.

As shown in Figure 20, the illustrated guide fingers 11g and IIh cooperating with wheels 15d and 16d, respectively, project into the incoming and outgoing sides of the nips between the rolls and are representative of the type of guide lingers used in the passes illustrated in Figures 8 to ll wherein the web or back portion of the blank IIb from the pass shown in Figure 7 is successively deformed to form C-shaped blanks ||c, IId, ||e and If with each successive blank having a more bowed or curved contour and a smaller gap between-the sides thereof.

The newly formed blank I Ic from the pass illustrated in Figure 8 is fed into the groove |03 of the guide finger 11g shown in Figure 20 where it is advanced in straddling relation on the rib |04 in the groove into the nip between the rolls 15d and 16d between the converging side walls |05 of the recess in the roll 16d as shown in Figure 9 to be forced into the bottom of the recess against the wall |06 thereof by the rounded Wall |01 on the periphery of the male wheel 15d, thus raising the blank to a higher level in the nip and forming the blank IId. The blank IId is then received in the groove |08 of the guide ngers 11h (Figure 20) in straddling relation around the rib |09 in the leading end of this groove. 'I'he rib |09 projects into the nip as far as possible while maintaining clearance relationship with the walls and the wheels.

The ribs |04 and |09 prevent rotation of the blanks in the grooves to insure the presentation of a series of properly aligned blanks to the next pass of the machine.

The blank ||d is deformed in the next pass of the machines by the wheels 15e and 16e. Thus, the female wheel has a very pronounced curval 1 ture in its bottom wall and the periphery of the male wheel 15e has a complementary curvature III to further bow the web or back portion 0f the blank.

The next pass of the machine shown in Figure l1 includes a substantially segmental circular bottom wall ||2 in the recess of the female wheel 16f complemented by a similar curved walls ||3 on the periphery of the male wheel 15j to produce the blank I If which is of substantially circular configuration but has a large gap between the edges thereof. This gap is held to desired dimensions by the side walls on the rim of male wheels which deforms the back portion or web portion of the blanks. Thus, as shown in Figures 9 to 11', the ends of the blank engage these side walls.

The succeeding passes oi the machine further deform the blank II in successive stages to produce blanks I Ig, Ilh, I Ii and the finished tubular pin I2 as shown in Figures 12 to l5, inclusive. These passes only work the exterior of the blanks, and the male wheel does not have a mandrel rim working the inner face of the bowed web portion of the blank. However, in' each instance, a rim rib is provided on the male Wheel to project into the tubular blank for preventing its rotation out of proper alignment.

As shown in Figure 21, the guide lingers 11i and 117' coacting with the wheels 15g and 16g of the next pass shown in Figure 12, exemplify the type of guide lingers that are used in all of the passes which close the gap of the tubular blank IIf from the pass illustrated in Figure 11. Thus, the guide linger 111 has a groove ||4 with a rib extending throughout its length. The blank IIJ from the pass shown in Figure 11 is fed through the groove I I4 in straddling relation around the rib ||5 into the nip .between the wheels 15g and 16g whereupon it is raised to the top of the groove ||4 to start to form the blank Ilg. This blank llg then enters the groove ||6 of the finger 117 and has its leading end straddling the rib ||1 in this groove |I6 before its trailing end leaves the rib I I5.

As best shown in Figure 12, the bottom wheel 15g has a tapered recess defined by converging side walls |I8 which extend inwardly into the wheel to curved bottom walls ||9. These walls I|9 extend inwardly to outturned sloping shoulders |20 forming abutments for the ends of blank as will be more fully explained. A rib I2I projects radially outward from the converging ends of the shoulders |20 for a distance which is less than the internal diameter of the blank Ilg so that the rib will not engage the inner wall of the blank.

The top wheel 16g has converging side walls |22 extending to a substantially semi-circular recess |23 around the periphery of the wheel. The blank IIg is formed by the wall |23 forcing the blank against the curved converging walls H9 until the ends of the blank engage the shoulders |20. The rib |2| cooperates with ribs ||5 and ||1 of the guide fingers to guide the blank through the nip and prevent its rotation.

The next pass shown in Figure 13 includes a bottom wheel 15h which has a recess with converging side walls |24 and with more pronounced curved ends |25 extending to shoulders |26 which are closer together than the shoulders |20 and have less taper than the shoulders |20. A rib |21 extends upwardly from the center of the recess beyond the shoulders |28. The top wheel has the converging side walls |28 fitting into the 12 recess of the bottom roll and converging to a fragmental circular recess |29 which is more of a true circle than the recess |23 of the preceding wheel. A blank I Ih is formed from the blank I Ig in the same manner described in connection with Figure 12.

In Figure 14, the bottom wheel 751' has a recess g with the converging side walls |30 and the rounded bottom walls I 3 I together with the shoulders |32 which are closer together than the shoulders |25 and have less taper than these shoulders. The rib |33 extending from the shoulders |32 is quite thin. The top wheel has the converging side walls |34 with a substantially true semicircular recess |35 and the blank IIi is formed from the blank Ilh to produce substantially the finished roll pin shape.

In the nal pass, illustrated in Figure 15, th bottom Wheel 157' has the side walls |31 converging to true circular arc portions |38 on opposite sides of slightly tapered shoulders |39 .which are quite close together and have a very thin rib |40 extending upwardly therefrom. 'I'he top wheel has the side walls |4| converging to a true fragmental circular recess |42. 'Ihe wheels 157 and '|67' thus cooperate to deform the blank IIi to the final tubular pin I2.

It will be appreciated that in each of the passes shown in Figures 12 to 115 the blanks are successively worked from their outsides to produce the true circular contour of the ilnished tubular pin. In each pass, the size of the gap in the blank is accurately controlled by anvil surfaces on the bottom wheel and these surfaces are tapered to control the planes of the ends of the blank.

After passage through the nip of the last rolls 15g and 16g, the finished tubular pins are discharged to a collecting bin through a chute |43.

From the above descriptions, it will be understood that, according to this invention, at metal stock such as spring steel strip stock is successively cut into slugs `which are fed in end-to-end relation through a number of passes of forming rolls or wheels which successively deform the slugs to produce the nal tubular pin in operations which are accurately gauged and uniformly reproduced on each successive blank. 'Ihe slugs and blanks are advanced in guide iingerswhich hold them in proper end-to-end relationship, and the forming rolls or wheels cause the advancement of the blanks. The wheel speeds are controlled so that jamming cannot occur. The guides are arranged to introduce the work to the passes at one level and to receive the work from the passes at another level before the trailing edge of the blanks leave the incoming guides. In this manner, the stock cannot be bent to follow the forming rolls, and very short pieces can be handled without danger of longitudinal deformaion.

It will, of course` be understood that various details of construction may be varied through a wide range Without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claims.

We claim as our invention:

1. A machine for making tubular pins and the like which comprises a roll mill having a plurality of pairs of forming wheels in spaced aligned relation, each pair of wheels including a male wheel having a mandrel forming surface and a female wheel having a shaping recess, an inlet guide projecting into the inlet sides of the nips 'between each pair of roll mill having a plurality of pairs of male and female forming wheels with contoured peripheries arranged to successively deform flat metal slugs into channel blanks, thence into c-shaped blanks and thence into tubular form to produce tubular pins having the desired cleft gap along their length, said female rolls being designed to receive the slugs and blanks in their radially outer portions, and said male rolls'being designed to force the slugs and blanks into the inner portions of the recesses of the female rolls, and guide means arranged to feed the blanks and slugs into the outer portions of the recesses and to receive the blanks and slugs from the inner portions of the recesses.

3. A machine for forming tubular pins from metal slugs which comprises a plurality of spaced pairs of forming rolls defining successive slug deforming nips for successively acting on the slugs, said successive nips being spaced apart a distance greater than the length of the longest slug acted upon so that no one slug can be simultaneously engaged in more than one nip, means guiding the slugs to successive nips, and means driving the successive pairs of rolls at successively increased speeds to automatically advance the slugs through the nips and between the successive nips without jamming the slugs.

4. A machine for forming short metal blanks into predetermined shapes including a. frame, a series of roll stands spaced along said frame and including a series of cooperating feeding and forming rolls providing a series of passes along said frame, power drive connections to said feeding and forming rolls so constructed and arranged as to drive each stand of said cooperating rolls at speeds progressively increasing from the first to the last roll stand, guide means adaptable to receive and guide the blanks in end-toend relation along said frame and extending into and out of the nips of each pair of forming rolls, and said forming rolls being so spaced that two nips never contact the same blank at the same time.

5. A machine for making relatively short tubular members with cleft gaps along their lengths which comprises a first pair of forming wheels defining a nip arranged to receive flat rectangular metal slugs in successive end-to-end relation, said nip being shaped to deform the side margins of the slugs into arcuately curved flanges, a plurality of successive pairs of forming wheels in spaced relation following said first pair of forming wheels and having contoured peripheries arranged to successively work the slugs through channel-shaped blank stages into a c-shaped blank stage, a final pair of forming wheels having contoured peripheries for receiving'pthe C- shaped blank from the preceding pair of forming wheels and including a peripheral male rib with tapered shoulders sized and contoured for controlling the width of the gap along the length of the blank and the shape of the side walls defining the gap, guide ngers between the pairs of wheels contoured to receive the blanks produced by the wheels for feeding the blanks in proper alignment to the next pair of wheels, said guide .fingers extending into the nips between the wheels oi' each pair for receiving the blanks before they are released from the nips, and means for driving successive pairs of wheels at progressively increased speeds for propelling the blanks through the guides to the successive nips without permitting two successive nips to simultaneously contact the same blank. i

.6. A machine for making tubes of relatively short length with cleft gaps of controlled width along their short length which comprises a plurality of pairs of forming wheels in spaced relation. each pair of wheels defining a forming nip having an inlet at a first level and an outlet at a dilerent level, said forming nips of successive pairs of wheels being contoured to successively deform flat rectangular metal slugs through channel-shaped blanks and C-shaped blanks into tubular form having a gauged cleft gap, guides between the pairs of rolls extending into the nips thereof and shaped to receive the blanks produced by the nips before the nips release the blanks, the guide on the inlet side of each nip being at a different level from the guide on the outlet side of the nip and in alignment with the inlet and outlet levels of the nips.

7. A machine for -making tubular pins from flat slugs which comprises a plurality of pairs of forming wheels in spaced relation, each pair of wheels defining a forming nip with an inlet at one level and an outlet at `a second level, and guides between the pairs of wheels having finger portions extending into the nips in alignment with the inlet and outlet sides thereof for feeding the blanks to the nips at one level and for receiving-the blanks from the nips at another level before the blanks are released from the nips, whereby the blanks are held against deformation along their lengths.

8. In a machine adapted for producing short tubular members from flat slugs, the improvement which comprises a pair of forming rolls having contoured peripheries defining a shaping nip with an inlet at one level and an outlet at a second level, an inlet guide projecting into the inlet side of the nip at said one level, an outlet guide projecting into the outlet side of the nip at said second level, the inlet guide having a shape conforming with the work piece entering the nip, the outlet guide being contoured to conform with the shape of the work piece leaving the nip, and said guides having leading ends in the nip positioned suiiiciently close together so that the outlet guide receives the leading end of the'work piece before the trailing end of the work piece leaves the inlet guide, whereby the work piece is held against deformation along its length while being transversely deformed in the nip.

HOWARD PETERS. EDWARD J. HAEDIKE.

K REFERENCES CITED The following references are of record in the le of this patent:

UNITED STA'I'ES PATENTS Number Name Date 225,835 Hooven Mar 23, 1880 334,361 Eppler Jan. 12, 1886 351,987 Lewis Nov. 2, 1886 (Other references on following page) UNITED STATES PATENTS Number Name Date Bray July 17, 1900 Millinger Feb. 6, 1906v Greeneld Apr. 3, 1906 Peirce July 3, 1906 Grant Oct. 5, 1909 Lane June 12, 1917 Hall Dec. 17, 1918 Miller Nov. 25, 1919 Muller Nov. 23, 1920 Muller Nov. 23, 1920 Muller Nov. 23, 1920 Number Name ,j Date Berg May 24, 1921 Kirsch Feb. 23, 1926 Bundy Sept. 7,1926 Poeppelmeier June 10, 1930 Bowler June 16, 1931 Birckmay'er Dec. 8, 1931 Klocke June 26, 1934 Rafter July 9, 1935 Keller Sept. 7, 1937` Cardwe11 Apr. 6, 1943 Wesselhoff Sept. 2, 1947 McKay ,Apr. 13, 1948 

